For housings of electronic devices such as a mobile phone, considering various factors, such as decorativeness, scratch resistance, processability and cost, those chosen as appropriate from resins have been used. A housing of a portable terminal in particular has been often constituted of materials such as plastics or resins (see Patent Document 1).
A gallery or a tunnel is high in temperature and humidity on the inside thereof and air therein is polluted, and hence its wall surface deteriorates fast. In addition, no daylight is shining on the inside of a gallery or a tunnel, and artificial lighting is therefore required during not only nighttime but also daytime. Great amounts of electric power are consumed by lighting of galleries and tunnels scattered throughout the country, and power savings have therefore been hastened.
As a material for the interior part of the gallery or tunnel, tiles with high reflectance have been used traditionally. The use of highly reflective tiles allows reduction in number of lighting fixtures, and it has yielded energy savings. In addition, visibility enhancement has been effected. As to the currently-used interior tiles for tunnels, application of coatings of glaze to their respective ceramic substrates has been carried out for the purpose of enhancing the ability to be cleaned, reflectance or strength.
For example, light-reflecting tiles for interior use of a tunnel have been described in Patent Document 2, wherein the tiles each has had a plurality of particulate asperities formed on a substrate surface thereof and the substrate surface has been coated with glaze for the purpose of increasing the strength thereof. Further in the document, the glaze rendered whitish by incorporation of zirconia into transparent glaze has been mentioned as a white glaze.
Furthermore, highly reflective white tiles to be used as a building material or wall material of buildings have been described in Patent Document 3, wherein there has been a description that contamination control treatment using glaze has been given to the tiles as required.